Republic of Ireland boss Martin O'Neill would reluctantly accept playing Euro 2016 games behind closed doors if the ongoing terror threat meant that was the only alternative.
UEFA insisted on Wednesday that it had no plans to keep supporters out of games at this summer's finals in France in the wake of Tuesday's attacks in Brussels.
However, O'Neill admitted that, should security chiefs decide that is the best solution to guarantee the safety of all involved, they would have to do it.
He said: "If someone wants to make an attack as happened yesterday, it's very, very difficult to deal with that, but overall the security that we're being provided with is really excellent and like everything else, I'd comply with anything that is happening.
"There's talk about matches being played behind closed doors, but the safety of people is of paramount importance and anything that is agreed upon, we will fall in line.
"If that is an alternative and it's the only alternative, then if we are going to have the competition, we may have to comply with it."
Ian Mallon, the Football Association of Ireland's director of communications, confirmed that the FAI is engaged in an ongoing security process and that it would be guided by the experts.
Mallon said: "Obviously Belgium has re-focussed attention on this terrible phenomenon of global terror.
"We at the FAI would be led by An Garda Siochana, the Department of Foreign Affairs and UEFA in all matters relating to security around Euro 2016 and we are in regular dialogue and consultation, and a process was already there pre-yesterday.
"We are absolutely engaged with that process and it continues, sadly."
Heightened security around the tournament is likely to have repercussions for both Ireland and their fans around their base in Versailles, with the atmosphere unlikely to be as relaxed as it was in Sopot four years ago.
O'Neill said: "The hotel that has been sorted out for us is actually very, very good. The possibility of players going into the town now might be a bit of an issue, whereas we though before that it looked really lovely.
"The town there, Versailles itself, is just really excellent, and it's only a three, four, five-minute walk as well, so all of those things looked pretty good.
"If, of course, security is tightened as it probably will be, then maybe the players might have to stay closer to the hotel.
"I don't think we want to turn away supporters, but at the same time security, I think people will realise that it might be very, very tight."
In the meantime, O'Neill is concentrating on Friday night's friendly clash with Switzerland and the game against Slovakia which follows it on Tuesday.
Midfielder Jeff Hendrick has returned to Derby for treatment on a long-standing shoulder injury, while Stoke striker Jonathan Walters is expected to return to the Irish camp ahead of the second game after heading home as he nurses a minor hamstring strain.
Skipper Robbie Keane sat out training once again on Wednesday, but O'Neill is confident he will be available for both games.
Meanwhile, O'Neill once again refused to be drawn on his own future with talks over an extended deal - his current contract expires after the finals - expected to take place soon.
He said: "Loads of things can happen between now and then and there's no point in turning around and telling you that there's an absolute degree of certainty about anything.
"What we want to do is not only try to enjoy the Euros if it's at all possible, but also try to make some sort of progress there as well, so we will see how things go. But who knows?"